The Peer-to-Peer (P2P) technology is a new network technology. In downloading a file, the speed of downloading the file is dependent on the computing abilities and bandwidths of participators in the network, instead of only a few servers.
A file to be downloaded may be downloaded to a P2P client by clicking a download link. However, the link might be broken during the process of downloading the file. The broken link means an invalid download link. In the case of the broken link, the P2P client cannot finish downloading the file.
In order to avoid the case that the file cannot be downloaded due to the broken link, the file for downloading is stored in the cloud for a backup purpose during the downloading of the file, and the download link corresponding to the file is also stored in the cloud. Then, a new link is generated for the backuped file stored in the cloud, and the new link is mapped to the download link aforementioned. In the case that the download link is broken, the new link aforementioned can still be found via the download link and used for downloading the backuped file in the cloud.
However, lots of the backuped files need to be stored in the cloud during the above downloading processes, thus the storage capacity of the cloud shall be large enough, and large bandwidth is required by the cloud to provide the backuped files. Therefore, maintenance and investment costs for the cloud are expensive.